The present invention relates to a lamellar decantation or clarification apparatus, of the type of the ascending hydraulic flux, wherein the liquid flows from bottom to top of the apparatus, and provided for the clarification of liquids, notably of drinkable, industrial and urban residual waters.
It is known that the efficiency of the lamellar decanters is essentially tied to the repartition quality of the liquid to be treated on the whole lamellar decantation surface.
According to the design of the lamellar modules or ducts, it is possible to distinguish between two correct repartition types. In the case of lamellar modules formed of parallel plates, the distribution takes place downstream of the module, that is at the outlet of the treated liquid, via weirs placed where the plates open and pertaining to each duct defined by two plates.
In the case of lamellar modules formed of tubes, it is not possible to envisage such a recovery of the liquid, and the only repartition via a series of perforated chutes or collectors above the modules is illusive; this is the reason why the liquid is often distributed from upstream, that is when the liquid to be treated is introduced in the apparatus, all along the decanter via a perforated channel providing for the equidistribution of the liquid.
This distribution is detrimental to the tubular module lamellar decanters which are actually capable of much higher performances than the parallel plate decanters since there is a risk of deposits and of a deterioration of the flocculated particules, or flocks, at the level of the distribution orifices. For avoiding the destruction of the flocks, distribution channels of very large capacity would have to be used, with the risk of extra deposits and at the cost of a non negligible size increase of the works.